Three species within the genus Chlamydia are clinically important because of their ability to infect and cause disease in a human host. Chlamydia trachomatis has been reported as the most common sexually transmitted disease in industrial societies and causes genital infections in both men and women. Chlamydia psittaci is responsible for a variety of respiratory tract infections. The most recently characterized and clinically important member of the Chlamydia genus is Chlamydia pneumoniae (C. pneumoniae) which also is responsible for respiratory tract infections and has been associated with coronary artery disease.
Perhaps because of its fairly recent characterization, the predominant methods for detecting C. pneumoniae in a test sample include isolation of the organism in culture, and serology testing. Isolation may include growing the organism in tissue culture cells to produce inclusion bodies which are then detected by fluorescently staining the inclusion bodies using a labeled species-specific-antibody. Serological testing requires two samples from an individual suspected of being infected with C. pneumoniae. Two samples are necessary because a significant number of individuals have antibodies to C. pneumoniae and a rise in antibody titer to C. pneumoniae or a change in antibody class (e.g. IgM to IgG) is measured as an indication of a recent C. pneumoniae infection. Because a rise in antibody titer or a change in antibody class is measured, acute and convalescent serum samples are taken. Unfortunately, these samples are often times taken weeks or even months apart. Hence, detecting a C. pneumoniae infection can be a time consuming process. Accordingly, there is a need for methods and reagents capable of detecting C. pneumoniae in a specific and timely manner.